Electric switches or plugs ordinarily have a plastic housing in which the electric parts are stationarily arranged. Therefore a plastic material is selected with a characteristic stability high enough to ensure the desired operating position of the individual parts, e.g. as contact blades. However these synthetic materials are normally not break-proof, which fact comes especially into existence, if it is intended to connect the switch or plug with other contact members and, indeed, by locking connections. When the parts provided for the locking connections are deflected, the parts are easily overstressed with the consequence that the plastic parts of the switch or plug break. If the plastic holding material is replaced by another synthetic material, e.g. an elastically moldable plastic material, it is ensured that the individual electric parts accommodated within the housing retain the position they occupy relative to each other, even under extreme strain on the switch or plug.